Live Merge will not complete its execution. There was a commit from master to 3.5 removing some states from the new command execution framework which was missing a few lines.
To test: Run live merge. Without this patch, it will never converge, despite partially failing or succeeding. Upon success, the system may operate normally afterwards (despite the command being in progress), but if the command failed the snapshot will remain locked.
Description should say "There was a commit _backported_ from master to 3.5 [...]". This bug only affects the 3.5 branch.
oVirt 3.5 has been released and should include the fix for this issue.